Tankless water heater cost
A whole-house tankless water heater typically costs $1,406 to $3,902 installed, averaging $2,641, according to Angi's August 2026 data. A small point-of-use unit costs a few hundred dollars. Switching from a tank often adds venting, gas-line or electrical work. Below you'll find what each source says, how to size a unit by GPM, tank vs tankless over the long run, and an estimator you can fill in with your own quotes.
Published cost ranges
These are national ranges as each source publishes them. None of them are our own prices.
| Source (date) | Installed range | Notes |
|---|---|---|
| Angi (updated Aug 3, 2026) | $1,406–$3,902 | Average $2,641 |
| HomeGuide (Jan 2, 2026) | $1,400–$5,600 | Electric to natural gas |
| Fixr (updated Jan 31, 2025) | $2,500–$4,500 | Average $2,811 |
By fuel (HomeGuide, Jan 2026)
| Fuel | Heater only | Installed |
|---|---|---|
| Electric | $600–$1,000 | $1,400–$3,000 |
| Propane | $1,000–$2,000 | $1,600–$4,500 |
| Natural gas | $1,500–$2,600 | $2,100–$5,600 |
Condensing vs non-condensing gas: condensing units cost more to buy. HomeGuide says non-condensing units cost about 25% less to install. Condensing models capture heat from the exhaust. A.O. Smith's Adapt+ condensing line, for example, is rated at 0.95 UEF and vents through PVC pipe. ENERGY STAR certifies gas tankless heaters at 0.95 UEF or higher.
Whole-house vs point-of-use
- Point-of-use (single-point): heater only, $150–$250 (HomeGuide) or $100–$300 for 0.5–2 GPM (Angi). These small electric units serve one sink or shower.
- Whole-house: heater only, $600–$2,600 (HomeGuide) or $450–$1,500 for 5–10 GPM (Angi).
Heater price by flow rate (Angi, Aug 2026)
| Flow | Heater only |
|---|---|
| 1–2 GPM | $150–$250 |
| 2–3 GPM | $200–$600 |
| 3–4 GPM | $300–$700 |
| 5–6 GPM | $400–$1,200 |
| 7–8 GPM | $500–$1,500 |
| 8+ GPM | $600–$2,000 |
Estimate your own job
Each line starts at a published range, mostly HomeGuide's (January 2026). Type in a figure from your own quote, store listing or building department and that line will use your number instead. Leave a box blank to keep the published range.
What's in the price
- The heater: fuel, flow rate (GPM), condensing or not, and brand. See the tables above.
- Labor: $600–$2,500 over 3–10 hours (HomeGuide), or $600–$1,850 (Angi). Fixr puts electric installs at $500–$1,000 and gas or propane at $900–$1,500.
- Venting (gas and propane): $100–$600 to replace exhaust vents. HomeGuide says old tank vents can't be reused.
- Gas line: tankless burners need more gas than a tank. HomeGuide puts a gas line upgrade at $350–$2,000, and Angi says adapting the line can cost up to $1,000.
- Electrical (electric units): a dedicated circuit costs $250–$900 and a panel replacement $850–$1,700 (HomeGuide). Angi notes that electric tankless units can draw 120 to 160 amps and may need a 200 amp service.
- Permit and removal: permits cost $50–$200 (HomeGuide) or $50–$100 (Angi). Removing the old tank costs $75–$500 (HomeGuide).
- Other parts: Angi lists a pressure regulator at $250–$350 and materials at $130–$280.
Sizing by GPM and temperature rise
A tankless heater's output is a flow rate at a given temperature rise. Size it in two steps:
- Peak flow: add up the fixtures you'll run at once. Angi's figures: shower 4–6 GPM (2–3 with a low-flow head), faucet 1–2, washing machine 2–2.5, dishwasher 1.5–2. Angi says the average home needs 5.5–7.5 GPM. HomeGuide's rule of thumb is 3.5 GPM for 1–2 fixtures, 5 GPM for 2–3 and 7+ GPM for 3–4.
- Temperature rise: subtract your incoming water temperature from your target. HomeGuide's example: 50°F groundwater heated to 115°F is a 65°F rise. Colder incoming water means a bigger rise and less flow from the same heater.
Then check the manufacturer's flow chart at your rise. ENERGY STAR, for example, requires certified gas units to deliver at least 2.8 GPM at a 67°F rise. The calculator below uses the standard physics: water weighs about 8.33 lb per gallon, and 1 BTU raises 1 lb by 1°F. So the output needed is GPM × 8.33 × 60 × rise, about 500 BTU per hour for each GPM per °F.
Tank vs tankless: lifetime cost
Tankless costs more up front but lasts longer. HomeGuide gives tankless heaters 15–20 years against 8–12 for a tank, and Fixr says 20+ years. HomeGuide's yearly energy figures are $220–$480 for gas tankless and $340–$540 for electric, against $250–$420 for a gas tank and $530–$600 for an electric one. A.O. Smith says its Adapt+ condensing unit can save up to $116 a year compared with a 50-gallon atmospheric gas tank.
The table below simply adds those published numbers over the period you choose. The low end assumes the longest lifespan, so fewer replacements. The high end assumes the shortest. Tankless includes a yearly professional flush ($110–$200, Angi). It ignores inflation, financing and rebates.
The federal Energy Efficient Home Improvement Credit no longer applies. The IRS says it covers qualifying property placed in service through December 31, 2025. Some cost guides still mention it, so don't count on it. Check your utility and ENERGY STAR's rebate finder for local rebates.
Descaling (flushing)
Minerals build up inside the heat exchanger, especially with hard water. Rinnai says to flush its residential units at least once a year, and to treat hard water. Fixr suggests every six months where water is hard. Rinnai's procedure circulates 4 gallons of undiluted white vinegar through the unit for about an hour, then rinses with clean water for 5 minutes. Rinnai says never to use chemicals, and strongly recommends isolation valves so the unit can be flushed. A professional flush costs $110–$200 (Angi). Always follow your own heater's manual.
- Gas: tankless gas units need a correctly sized gas supply, and gas work must be leak-tested. If you smell gas, leave the building and call your gas utility or 911 from outside.
- Venting and carbon monoxide: use only the vent materials and routing in the heater's manual, because condensing and non-condensing units vent differently. Poor venting can expose you to carbon monoxide. Fit a CO alarm nearby.
- Electrical load: whole-house electric tankless units can draw 120 to 160 amps (Angi). Have a licensed electrician check your panel's capacity and run the circuits. Turn off the breaker before any work.
- Scalding: the CPSC recommends hot water no hotter than 120°F.
- Permits: many jurisdictions require a permit and inspection for gas, venting and electrical changes. Hire a licensed plumber, and a licensed electrician for electrical work. In many places the law requires it.
Getting quotes
- Ask for an itemized quote: heater make and model with its GPM at your temperature rise, labor, venting, gas or electrical work, permit and removal.
- Ask whether isolation valves and a scale filter or water treatment are included.
- Compare warranties on the heat exchanger, the parts and the labor.
- Check the installer's license with your state licensing board.
Related: water heater replacement cost (tank and tankless), heat pump installation cost, how to fix a leaky faucet, how to fix a running toilet, and the plumbing guides.
FAQ
How much does a tankless water heater cost installed?
Angi's August 2026 data puts a tankless water heater at $1,406 to $3,902 installed, averaging $2,641. HomeGuide (January 2026) gives $1,400 to $5,600, and Fixr $2,500 to $4,500.
Is a gas or electric tankless water heater cheaper?
Electric is cheaper to buy and install. HomeGuide puts an installed electric tankless heater at $1,400 to $3,000, propane at $1,600 to $4,500 and natural gas at $2,100 to $5,600. Gas units usually need new venting and sometimes a larger gas line. Electric units may need a new circuit or a panel upgrade.
What size tankless water heater do I need?
Add up the flow rates (GPM) of the fixtures you'll run at the same time, then check that the heater delivers that flow at your temperature rise. The rise is your target temperature minus your incoming water temperature. Angi says the average home needs about 5.5 to 7.5 GPM.
Is there a federal tax credit for a tankless water heater?
Not for new installs. The IRS says the Energy Efficient Home Improvement Credit covers qualifying property placed in service through December 31, 2025. Some cost guides still mention it. Check your utility and ENERGY STAR's rebate finder for local rebates.
How often does a tankless water heater need descaling?
Rinnai says to flush its residential units at least once a year, and more often with hard water. Fixr suggests every six months where water is hard. Angi puts a professional flush at $110 to $200.
Sources
All checked October 13, 2026. Dates are each page's own published or updated date.
- Angi, How much does a tankless water heater cost?, updated August 3, 2026: installed range and average, units by type and GPM, labor, permits, gas line, electrical draw, removal, regulator, materials, flush, fixture flow rates, household GPM.
- HomeGuide, Tankless water heater cost, January 2, 2026: costs by fuel and type, labor, supplies, permits, circuit, panel, gas line, venting, removal, hourly rates, sizing, energy costs, lifespan.
- Fixr, Tankless water heater installation cost, updated January 31, 2025: range, average, labor by fuel, descaling interval, lifespan.
- Rinnai, Flushing my Rinnai tankless water heater: flush interval, vinegar procedure, isolation valves.
- ENERGY STAR, Whole-home tankless gas water heaters and key product criteria: UEF 0.95 and 2.8 GPM at a 67°F rise.
- A.O. Smith, Adapt+ premium condensing gas tankless water heaters: 0.95 UEF, PVC venting, up to $116/yr savings claim.
- Angi, How much does water heater replacement cost?, updated July 20, 2026: electric tankless draw of 120–160 amps and possible 200 amp service.
- IRS, Energy Efficient Home Improvement Credit: property placed in service through December 31, 2025.
- US CPSC, Avoiding tap water scalds (PDF).